PHP to achieve the search location and calculate the two-point geographic distance between instances _php instances

Location Search
LBS, which stores the latitude and longitude coordinates of each location, searches for nearby locations and establishes a geographical index to improve query efficiency.
MongoDB geolocation Index, 2d and 2dsphere, corresponds to planar and spherical surfaces.

1. Create lbs collection Storage location coordinates

use lbs;  Db.lbs.insert (   {     loc:{       type: "point",       coordinates: [113.332264, 23.156206]     },     name: "Guangzhou East railway Station"   } )  Db.lbs.insert (   {     loc:{       type: "point",       coordinates: [113.330611, 23.147234]     },     name: "Forest and West"   })  Db.lbs.insert (   {     loc:{       type: "point",       coordinates: [113.328095, 23.165376]     },     name: "Balance Stand"   

2. Create a geo-index

Db.lbs.ensureIndex (   {     loc: "2dsphere"   

3. Query for nearby coordinates
The current position is: Times Square,
Coordinate:

113.323568, 23.146436

Search nearby points within a kilometer, sorted by near to far

Db.lbs.find (   {     loc: {       $near: {         $geometry: {           type: ' point ',           coordinates: [113.323568, 23.146436]         },         $maxDistance: +       }     }   

Search results:

Copy the Code code as follows:

{"_id": ObjectId ("556a651996f1ac2add8928fa"), "loc": {"type": "Point", "coordinates": [113.330611, 23.147234]}, " Name ":" Forest and West "}

The PHP code is as follows:

<?php//Connect MONGODB function conn ($dbhost, $dbname, $dbuser, $dbpasswd) {$server = ' mongodb://'. $dbuser. ': ' $dbpasswd. ' @ '. $dbhost. '   /'. $dbname;     try{$conn = new Mongoclient ($server);   $db = $conn->selectdb ($dbname); } catch (Mongoexception $e) {throw new errorexception (' Unable to connect to DB server. Error: '.   $e->getmessage (), 31); } return $db; }//Insert coordinates to MongoDB function add ($dbconn, $tablename, $longitude, $latitude, $name) {$index = array (' loc ' = ' 2dsphere ')   ; $data = Array (' loc ' = = Array (' type ' = ' = ' point ', ' coordinates ' = = Array (doubleval ($lon   Gitude), Doubleval ($latitude))), ' name ' = = $name);   $coll = $dbconn->selectcollection ($tablename);   $coll->ensureindex ($index);   $result = $coll->insert ($data, Array (' w ' = true)); Return (Isset ($result [' OK ']) &&!empty ($result [' OK '])? True:false; }//Search nearby coordinates function query ($dbconn, $tablename, $longitude, $latitude, $maxdIstance, $limit =10) {$param = array (' loc ' = = Array (' $nearSphere ' = = Array (' $geometry ' = = A          Rray (' type ' = ' point ', ' coordinates ' = ' = ' Array (doubleval ($longitude), Doubleval ($latitude)),    ), ' $maxDistance ' =-$maxdistance *1000));   $coll = $dbconn->selectcollection ($tablename);   $cursor = $coll->find ($param);      $cursor = $cursor->limit ($limit);   $result = Array ();   foreach ($cursor as $v) {$result [] = $v; } return $result;  } $DB = conn (' localhost ', ' lbs ', ' root ', ' 123456 ');   Randomly insert 100 coordinate records for ($i =0; $i <100; $i + +) {$longitude = ' 113.3 '. Mt_rand (10000, 99999);   $latitude = ' 23.15 '. Mt_rand (1000, 9999);   $name = ' name '. Mt_rand (10000,99999); Add ($db, ' lbs ', $longitude, $latitude, $name); }//Search for points within one kilometer $longitude = 113.323568; $latitude = 23.146436; $maxdistance = 1; $result = Query ($db, ' lbs ', $longitude, $latitude, $maxdistance);  Print_r ($result);?>

To demonstrate PHP code, you first need to create users and execute auth in MongoDB's lbs. Here's how:

Use lbs; Db.createuser (   {     "user": "Root",     "pwd": "123456",     "roles": []   })  Db.auth (   {     "user ":" Root ",     " pwd ":" 123456 "   

Calculate the distance from the two-point geographic coordinates
Function: Calculates the spherical distance between two points according to the latitude and longitude of pi and earth radius coefficients and coordinates of two points.

Get two point coordinate distance:

<?php/** * Calculates the distance between two points of geographic coordinates * @param decimal $longitude 1 beginning Longitude * @param decimal $latitude 1 beginning latitude * @param Decimal $longitude 2 Finish Longitude * @param Decimal $latitude 2 End latitude * @param Int $unit Unit 1: M 2: km * @param Int $decimal precision reserved decimal place * @return Decimal */function getdistance ($longitude 1, $latitude 1, $longitude 2, $latitude 2, $unit =2, $decimal =2) {$EARTH _radius = 6 370.996;  The radius coefficient of the earth $PI = 3.1415926;  $radLat 1 = $latitude 1 * $PI/180.0;  $radLat 2 = $latitude 2 * $PI/180.0;  $radLng 1 = $longitude 1 * $PI/180.0;  $radLng 2 = $longitude 2 * $PI/180.0;  $a = $radLat 1-$radLat 2;  $b = $radLng 1-$radLng 2;  $distance = 2 * ASIN (sqrt (Pow (sin ($a/2), 2) + cos ($radLat 1) * cos ($radLat 2) * POW (sin ($b/2), 2)));  $distance = $distance * $EARTH _radius * 1000;  if ($unit ==2) {$distance = $distance/1000; } return Round ($distance, $decimal);} Start coordinates $longitude1 = 113.330405; $latitude 1 = 23.147255;//end point coordinates $longitude2 = 113.314271; $latitude 2 = 23.1323; $distance = ge Tdistance ($longitude 1, $latitude 1, $lOngitude2, $latitude 2, 1); Echo $distance. ' m '; 2342.38m$distance = Getdistance ($longitude 1, $latitude 1, $longitude 2, $latitude 2, 2); Echo $distance. ' Km '; 2.34km?>

